Liquid fuel burner



March 30, 1937. v. s. TODARO LIQUID FUEL BURNER Filed Aug. 10, 1934 2 Sheets-Sheet 1 INVENTOR.

I M/cE/VT 5. 730 920 ATTORNEYS March 30, 1937. v. s. TODARO LIQUID FUEL BURNER 2 Sheets-Sheet 2 Filed Aug. 10, 1934 INVENTOR. l m cus-NT 6. 760,420

BY a

ATTORNEYS Z-SnEt-r h sussv- ,2

Patented Mar. 30, 1937 LIQUID FUEL BURNER 7 Vincent 8. Todaro, Brooklyn, N. Y.

Application August 10, 1934, Serial No. 139,215

3 Claims. (Cl. 158-36) trolling arrangement for oil or liquid fuel burners of the pot type.

In liquid fuel burners of the pot type there is 5 usually provided a circular pot, which may contain an absorbent or porous wick material, which porous material is saturated at initiation of operation with oil and may be initially ignited by a pilot flame.

The pot may be supplied from an oil tank which in most instances, is set substantially higher than the top of the burner pot so that there will be a suflicient gravity feed. The oil 5 pressure at the burner is preferably maintained constant irrespective of the amount of oil in the tank by providing a constant level control so that the same head will be applied to the burner pot at all times.

The liquid fuel supply from the supply tank to the burner passes through a filter, a main shut-01f valve, a measuring valve for regulating the oil supply when the burner is in operation, and an electromagnetically controlled valve 25 which may be connected to a thermostat in one of the rooms of the home to be heated.

In the usual type of pot burners, the pilot flame is maintained by by-passing part of the main oil supply through another measuring valve, which last-mentioned valve is always maintained open,

so that there will be a continuous small feed of oil suficient to maintain the small pilot flame.

The burner is supplied .with air by a motor driven blower which is usually turned on at the beginning of cold weather in fall and left running without cessation until warm weather in spring regardless of whether or not liquid fuel supply may have been cut off during the night and/or at periods during the day when the temperature in the house raises to too high a degree.

After each shutdown due to elevated temperature above a predetermined range which it is desired to maintain in the household, or due to shutdown at night, the flame will burn down to a considerable extent in the pot before it becomes extinguished. After the fuel supply has been cut off in this manner, the level of oil in the pot often will burn down to the bottom of the pot.

When subsequently the burner is started in the morning or when the temperature has fallen in the household and the oil supply is turned on, there will be a considerable lag, often as much as 10 or 15 minutes, before the oil will completely fill the pot. When oil completely fills the pot a full flame will envelop the entire top surface of type previously described in which the burner the pot, often rising to as much as 12 inches above the'porous wick material. In a short time the upper part of the wick or porous material will become red hot due to the intense heat engendered, and the oil level will drop to about -within 2 inches of the top of the wick. When this occurs, the oil will be vaporized by the heated wick granules below the upper surface of the wick. The vapors will be superheated as they rise between the voids in the granules, and as they leave the upper surface of the wick they are mixed with the air blast of the blower and are then ignited.

Upon extinguishment of the flame when the level of the oil has burned down sufllciently to extinguish the main flame and merely leave the a pilot flame, this pilot flame will keep the pot fairly warm. Since the oil'supply to the pot for the pilot is in part distributed over the entire porous material body in the .pot, vaporization often takes place in other parts than at the pilot 20 flame.

These vaporized unburned gases will be caught up by the blast from the blower which is continuously operating and will be forced by said blower into the boiler and from the boiler into the house.

This not only causes a loss of liquid fuel, but in acl\'.lition, creates unpleasant odors in the household. "Moreover, the lag in igniting the main burner flame after the main valve has been thermostatically opened to supply liquid fuel to the liquid burner, is also found to be undesirable.

An object of the present invention is to provide a heating installation or oil burner of the 35 will be operated most economically in respect to fuel and power consumption without danger of the blower blowing unburned or partly burned fumes of the liquid fuel through the household to be heated with a relatively small pilot flame, and without a long lag between the operation of the thermostatic apparatus to open the fuel supply to the pot and the ignition of the flame to initiate the heating operation. 45

Another object is to provide an improved burner construction of the pot type in which the flame will be promptly ignited bythe thermostatic control, even though the burner has been extinguished for a considerable period of time 50 and the level of oil has dropped to the bottom of the pot.

Another object is to provide an improved pilot construction of the oil burner pot type in which the maintenance of the pilot flame will not re- 55 25 fllled and is ready to be ignited.

will be in whole or part isolated from the main body of ceramic material in the pot with the result that the heating due to the burning pilot will not tend to cause arising or creation of fumes from the liquid fuel.

In the preferred construction according to the present invention, the pilot flame is separately fed through a conduit independent of the conduit -feeding the main pot.

In this embodiment of the present inventionv objects nular casing and protectlng the shell II from the direct heating action of the flame.

The central air passage I 3 is partly. closed by.

the shield I 8, which directs the air current out over the top surface of the porous material I1 I as indicated by the arrows I9. I

Connected to one part of the annular enclosure and preferably cast integrally therewith or welded thereto is the pilot enclosure which extends the entire depth of the shell ii and has an opening atthe top of the pot II. The

pilot enclosure 20 is filled with porous material 2| of the same composition as the porous ma-, terial II, the porous material 2i serving as a wick; V y w The porous material l1 andthe porous material 2| are separately supplied with fuel by the inlet connections 22 and 23 from the conduits C and D respectively.

20 there is also provided an accelerator oil or liquid fluid feed which will quickly flll thepot' after shut-down when the main flame is again to be ignited and which will initiate operation of the blower only after the pot has been completely This accelerator device is preferablycontrolled bythe fuel level in the pot and it serves to open an auxiliary. feed line into the pot during the.

period of reinitiation of the burner operation, which auxiliary feed is cut off as soon as the pot has been flied and the flamehas been ignited.

The above and other objects of the present application will appear moreclearly from the following detailed description when taken in connection with the accompanying drawings showing preferred embodiments of the inventive idea.

In the drawings: Figure 1 is a diagrammatic layout of the 4 burner arrangement according to one embodiment.

Figure 2 is a side view of the arrangement'of Fig. 1 upon the line 2--2 of Fig. 1.

Figure 3 is a cross sectional view upon an ennism.

Figure 41s a transverse sectional view upon the line 4-4 of Fig. 3, and w Figure 5 is a schematic wiring diagram. Refening to Figs. 1 and 2, the pot E is prospectively fed by the oil conduits C and D. The pot is supplied with air by the blower E which is driven by the motor F. The liquid fuel is supvided with a pilot enclosure B, which are re- The line D is'fed directly through the connection 24 from the fllterK and the liquid flowing through this line is preferably regulated by the measuringneedle valve indicated at 25.; The

line C which leads to the main body of themrous material in the pot II is normally fed through the branches 32, 26 and 21 and may also be fed through the branches 24 and 2| during initiation of the operation of the burner. The branch 32 carries the needle or measuring valve 29. The conduits leading to .the main C from the fllterK are respectively p ovided with solenoid control valves H and I.

During normal operation when the burner is operating the main fuel supply will be by way of the main supply line 0. the filter K, the needle valve 2., the solenoid control valve H and the minimal as, 20, 21 and c to the inlet a to the larged scale ofthe accelerator control mechamain body of ceramic material l'l. During this operation the motor F and the fan E will be actuated to force a suitable air supply through the conduit i4 and the passages l2 and I) to maintain the flame at the top of the body of ceramic material.

Also during this period the solenoid valveI will be closed. When the temperature rises to too high a degree in the house, the thermostatic arrangement T (see Fig. 3) will close the solenoid H and cut 03 the supply of fuel to the ceramic mass l1, leaving only the supply D to the material, nor will it be necessary to maintain a substantialsupply of oil to the body merely to assure the small-pilot flame. This will result in a decrease and elimination of the unburned or 5 and 2, and it is formed of an outer shell i0, and

an inner annular shell ll spaced from said outer shell Ill. These two shells form an annular passageway l2, and a central air passageway i3. The air is blown into thesepassageways l2 and 7 ll by the conduit ll, which is connectedto the bottom of the outer container II at II. .The V annular refractory enclosure ii encircles" the top of the pot and controls the outlet of the annular space l2 directing the air inwardly across the topof'tbe ceramicmaterial llinthe anpartly burned oil vapors which tendto pass into the house.

When the thermostatic control indicated at T in Fig. 3 cuts off the solenoid valves H and-I, see Figs. 1 ,and 2, before the main flame in the pot A becomes extinguished the oil level will have descended substantially within the pot and sometimes to the bottom of the enclosure ll.

Subsequently when through the thermostat.- T of Fig. 3 solenoid valve H is opened ten or flfteen minutes often will elapse withqthe fan E and motor F running, before the ceramic or porous material I! will have been suiiiciently saturated with oil to beignited and-to enable the burner to start its normal operation. 7

A particular feature of the present invention resides in the provision of a control system to assure that the pet will promptly flll with liquid connected the sleeve 5! by the flange 52.

fuel and be ignited when the Ihermostat control opens the solenoid valve H and further to assure that the fan E will not be operated until the pot A has been filled with liquid fuel to the desired level. This is accomplished by an auxiliary solenoid valve I and the control mechanism shown diagrammatically in small scale in Figs. 1 and 2, the control mechanism being shown on a larger scale in section in Figs. 3 and 4.

Referring to Figs. 3 and 4 the control mechanism consists of an enclosure 35 having a lower portion 36 of reduced diameter which is in communication with the conduit C by means of the T-fltting 37 and the nipple 38.

The nipple 38 is threaded at 39 into the stem 40 of the T-fitting and at M into an opening in the central portion of the bottom 42 of the lower portion of the casing 36. The vertical and transverse passages 44 respectively establish communication between the interior of the casing 35 and the conduit C with the result that the level of the liquid fuel in the casing 35 will be the same as the level of fuel in the pot A.

The casing 35 is provided with a cap 45 which is screwed to the casing as indicated at #36. The

central upper portion oi the cap is provided with an opening receiving the drilled and tapped lug 41 which in conjunction with the drilled and tapped projection 48 of the plug 38 and the bottom of the casing 35 receives the central guide rod 49, which extends axially through the entire height of the casing 35.

Received upon the rod 49 is the hollow annular metal float 50 to the upper portion of which is To the upper portion of the sleeve is threaded at 53 the cult element 54 which carries the pin 55.

The opposite ends of the pin 55 slide in the slots 56 in the clevis portion 51 of the lever 53. The lever 58 is pivoted at 59 on the slide to, which slide 60 may be adjusted on the bracket 6| by the set-screw 62. The bracket 6! is held on the casing 35 by the foot 63 and the screws 6d.

Connected at 65 to the lever 58 by the bar 36 and the band 61 is the right angular mercury tubular switch 68, which at its opposite ends is provided with the contacts 69 and 10.

The contacts 69 lead to the connections H which control the operation of the solenoid valve I while the contacts lead to the connections 12 which control the operation of the motor F,

driving the air fan E (see Fig. 1).

The broken lines 13 and I4 respectively represent the electrical connections or circuits leading from the contacts II and 12 to the solenoid valve I and the motor 14. The electrical conduits 75 lead to the main solenoid valve H.

In normal operation the valve H will be open and the motor F will be operating. When the temperature rises too high the thermostatic control T of Fig. 3, will act to open the circuits M and 15.

When the thermostatic control T so operates the motor F, and the main solenoid control valve H are closed.

Before the temperature will have dropped to a suflicient degree to cause the thermostatic control to closeagain the circuits 14 and 15, the level of liquid fuel in the pot A will have dropped from the level indicated by the line 16 and by the elevated position of the float 50 in Fig. 2 to a lower level indicated by the lower position of the float in Fig. 3.

In the position of Fig. 3, the mercury indicated at I02 in the tube 68 will have descended into the lower arm closing the contact 33 and opening the motor circuit ll. At this time however, no current flow will result since the lines have been opened by the thermostatic control T.

When the temperature in the enclosure or house being heated drops sufllciently, the thermostatic control T will close energizing the circuits l3 and 15, with the result both the solenoid valves H and I will be opened. The solenoid valve I usually has a greater opening than the solenoid valve H so as to permit more rapid flow of fuel to the pot A to saturate the porous material H. The motor F, however, will not be initiated since its circuit will be opened at the contact 10 with the angle mercury switch 38.

However, as soon as the level of the oil in the enclosure 35 and in the pot A have risen to the position indicated at 16 in Fig. 2, the elbow 68 in Fig. 3, will have been tipped sufficiently to open the contact 69 and close the contact 10. This will result in the initiation of the motor F and operation of the fan E and will cut off the accelerator valve I, whose circuit will now be opened.

When operation again ceases, due to the thermostatic control T opening the power circuit, the cycle will be repeated and the float 50 will then descend, opening the contact it in the circuit of the motor F and closing the contact 69 in the circuit of the solenoid valve I.

The vent 16 serves to permit the ready escape of air from the enclosure 35 when the oil level changes in the lower portion of such enclosure 36.

It is thus evident that by the arrangements of the present invention, a positive automatic mechanical control of the motor blower is obtained, so that the motor will not be operated until a predetermined oil level has been obtained in the burner pot A. At the same time the provision of a separate enclosure 20 for the pilot will insure a minimum consumption of oil. These features will eliminate the blowing of unburned and partly burned fuel gases into the boiler and into the household, and, moreover, will result in a substantial economy in the utilization both of the fuel and electric current by controlling the operation of the blower E. 7

By accelerating the pot filling from low to big flame or from pilot flame to normal operating flame, according to the construction of the present invention, it is possible to make the pot burner immediately effective to supply the necessary heat in response to a heat demand evidenced by closing of the thermostatic control as are mechanical atomizing burners, as a result assurance will be had that the burner operation will be promptly initiated after the thermostat has been of the burner, both the fuel and electric power' will be greatly economized with advantageous results.

It is to be understood that the invention is to be broadly directed to automatic level controlsfor pot burners whether or not such burners contain ceramic or other such materials.

Instead of a double shell pot shown in Figs. 1 and 2, a single shell pot construction might be em-v main regulating valve.

ployed with the refractory material. It positioned around the single shell. Moreover, by cutting ofl the blower and the blast of air during shutdown periods, it is possible to have a much smaller pilot, since in the present invention it does not have to resist the force of the. air blast. The natural draft will be sufficient to maintain the pilot flame in clear and smokeless condition.

By regulating the blower E by the level of oil in the pot, assurance is had that the pilot flame will not be blown out by the blower since when the level of the pot in the present invention burns suillciently low to leave only the pilot flame, the

mercury switch 88 will be actuated to open the the level of the oil in the burner, a much more,

satisfactory arrangement is had than with time devices and/or electrical resistances, employed to start and/or to stop the blower a predetermined length of time after the opening or closing of the These devices are not satisfactory since the length of time .of filling the pot will vary with the quality of oil and porosity of wick material, as will also the time required for permitting the main flame from the, pot to become extinguished when burned down to the lowermost oil level in the pot.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is herein reserved to make such changes as properly fall within the scope of the appended claims.

What is claimed is:

1. In combination with a liquid fuel burner of the bowl type having a motor operated air feeding means and a fuel feeding means comprising a main electrically actuated valve which is opened when energized, an auxiliary electrically actuated valve which is opened when energized and connected, in parallel relation with said main valve whereby when both valves are opened the rate of fuel feed is excessive; a control circuit including said motor, the actuating means switching mechanism responsive to the level of 2. In combination with a liquid fuel of the bowl type having air feeding means and l a fuel feeding means comprising a main valve operable to maintaina properfuel level during normal operation, an auxiliary electrically actuated valve which is' opened when energized and connected in parallel relation with said main valve whereby when both valves are opened the rate of fuel feed is excessive, said auxiliary valve serving to flll the bowl quickly to prime the burner to initiate operation; a control circuit including actuating means for said auxiliary valve. a main control switch and switching mechanism responsive to the level of fuel in said bowl con-e trolling energization of said auxiliary'valve and operable when the fuel level is too low to initiate operation quickly to energize said auxiliary valve and to deenergize said auxiliary valve when the desired priming level is attained.

3. In combination with a liquid fuel burner of the bowl type having a motor operated air feed ing means and a fuel feeding means'com prisin g main control switch. means for priming the burner to a proper fuel level for normal operation, and switching mechanism responsive to the level of fuel in said bowl controlling energization of said motor and operable when said main switch is closed and the fuel level is too low for initiation of proper burner operation to deenergize said motor and when the fuel level has been primed to proper operating levelto energize said motor.

VINCENT S. TODARO. 

